There is a shift control system for an industrial vehicle such as a wheel loader known in the related art that automatically changes a speed stage at a transmission when the vehicle speed becomes a setting speed. For example, when a wheel loader performs a work of loading soil onto a dump truck or the like, the vehicle speed may unintentionally fluctuate if the speed stage is changed at the time of approaching the dump truck. Accordingly, there is a shift control system known in the related art that is configured to hold a set speed stage for a predetermined period of time when the height of a working machine device (bucket) that is calculated from an angle of a lift arm or the like becomes equal to or greater than a setting height (refer to the patent literature 1).